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Why does pushing down on the long arm of a lever lift a load on the short arm?

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A diagram displays six types of simple machines with labeled illustrations: inclined plane, wedge, screw, lever, wheel and axle, and pulley, each shown with real-world examples like ramps, axes, screws, seesaws, door handles, and pulleys lifting objects. — simple machine Six simple machines for transforming energy into work.

A lever functions as a simple machine by using the principle of mechanical advantage to amplify physical force.123

When you push down on the long arm of a lever, you are applying a force over a greater distance from the fulcrum than the load on the short arm. Because the lever is a rigid bar supported by the fulcrum, this downward motion is transferred and converted into an upward force at the other end.12

The amount of force amplification is determined by the ratio of the lengths of the two arms. For example, if the long arm is five times longer than the short arm, the force exerted on the load will be five times greater than the force you apply. Essentially, the lever allows a small force applied over a longer distance to perform the work required to lift a much heavier weight over a shorter distance.12